Hi everybody !
Griffey95's solution is pretty good but I just want to show you that.
Thirst thing, join a clan with a lot of members (Trueachievements is a good one, because there are members with all kind of skill playing)
Choose the car you're good with.
Start a circuit race, each lap slow down the much you can when the finnish line is near you (set a good time too, because if you don't, your next rival will get you 250Cr). Complete the race.
to play against your rival (don't forget to raise difficulty for more Cr) and beat it! (starting with 1.000Cr is enought it will rise up after 3/4 races).
You win about 6.000/7.000Cr by beating a rival with 1.000Cr, beating a 5.000Cr rival will give about 16.000Cr. 16.000Cr/1min20 with loading times = 240.000Cr per 15 minutes with loading times.
The only thing you have to do is to slow down as much as you can to beat your rival with the fewest time difference (less than 0.00.100s is the more profitable).
I started my rivals time with 1min11s and in the last race I did in the video I was only 1min07s with about 15 rivals beaten.
If you break too much and crossed the line after your rival, simply press
and replay the part you failed.
(You can find shortest race with 55s a lap).
Once the challenge is too difficult for you, search a new race, and repeat. (I got 890.000Cr with 3 races).
I made a video for convenience.
Hope it could help some of you
, if you thumb down please explain why.
Sorry for my english, I am not bilingual.